Do you need to register?
You need to register if you have to send a tax return and you've never done one before (or HMRC closed your record). The most common reasons are becoming self-employed, renting out property, or having untaxed income HMRC doesn't know about. Our checklist on whether you need to file covers every common situation.
If you've registered in the past, don't register again — you already have a UTR. Find it with our UTR guide and just file the return.
The registration deadline
You must tell HMRC by 5 October after the end of the tax year in which you need to pay tax. The tax year runs from 6 April to 5 April — see tax year dates.
| Tax year | Register by | File online by | Pay by |
|---|---|---|---|
| 2025/26 (6 Apr 2025 – 5 Apr 2026) | 5 October 2026 | 31 January 2027 | 31 January 2027 |
| 2026/27 (6 Apr 2026 – 5 Apr 2027) | 5 October 2027 | 31 January 2028 | 31 January 2028 |
Missed 5 October?
Register straight away. If you owe tax and registered late, HMRC can charge a 'failure to notify' penalty based on the tax owed, so the sooner the better.Useful tool
Not sure you need to register? Check the common reasons first.
Which registration route to use
| Your situation | Route on GOV.UK |
|---|---|
| Sole trader / freelancer / gig work | Register as self-employed (this also sets up your Class 4 National Insurance) |
| Landlord, investment income, High Income Child Benefit Charge, other untaxed income | Register as not self-employed |
| Partner in a partnership | Register as a partner (the partnership registers separately) |
Company directors usually only register if they personally have income to report, such as dividends over the allowance — see company directors.
What you'll need
- Your National Insurance number.
- Your full name, date of birth, address, phone number and email.
- The date you started self-employment or started receiving the income.
- For self-employed: your business name (if any), business address and type of work.
- A Government Gateway or GOV.UK One Login account (you can create one during registration).
Step by step
- Go to the Self Assessment registration service on GOV.UK.
- Choose your route: self-employed, not self-employed, or partner.
- Sign in or create your account and confirm your identity.
- Enter your personal details and the date your income started.
- Submit. HMRC will post your UTR — usually around 15 days later, and longer if you live overseas.
- If HMRC sends an activation code for online services, use it before it expires.
After you register
Once you have your UTR you can prepare and send your return any time after the tax year ends on 5 April. You don't have to wait until January — filing early just means you know what you owe sooner. You still pay by 31 January.
Gather your P60, invoices, bank interest statements and rental statements, then start your return with TaxGo. Upload what you have, answer only what's missing, and your return is prepared ready for submission.
Coming up: Making Tax Digital
If your self-employment and property income is over £50,000 (from April 2026), £30,000 (from April 2027) or £20,000 (from April 2028), you'll also need to send quarterly updates. See Making Tax Digital for Income Tax.